Vitrectomy

The vitreous is a clear jelly that fills most of the eye and sits against the retina. With age, disease or injury it can pull on the retina, cloud with blood or carry infection. In a vitrectomy, the surgeon makes three openings in the white of the eye, each smaller than a millimetre, and passes in a light, an infusion line that keeps the eye's shape and a fine cutter that removes the gel. With a microscope and special lenses, the surgeon can then work directly on the retina: flattening a detached retina and sealing its tears with laser or freezing treatment, peeling a thin membrane from the macula, closing a macular hole or removing blood and scar tissue. At the end, the eye is filled with fluid, air, gas or silicone oil. The eye makes its own fluid afterwards, so the vitreous does not need to be replaced.

A retinal detachment, often noticed as new floaters, flashes of light and a shadow or curtain spreading across the vision, is the most urgent reason for vitrectomy, and it needs assessment within a day or so. A macular hole causes a blank or distorted spot in the centre of vision, while an epiretinal membrane, a thin layer of scar tissue on the macula, makes straight lines look wavy and blurs reading vision. In diabetes, fragile new vessels can bleed into the vitreous or pull the retina away, and vitrectomy clears the blood and releases the traction when laser and injections are not enough. Other reasons include severe infection inside the eye, injury, lens fragments that dropped back during cataract surgery and, in selected cases, very dense floaters that disrupt daily life. Planned operations such as membrane peeling, macular hole repair or diabetic surgery are the ones that suit travel well.

Most vitrectomies are done under local anaesthesia: an injection around the eye numbs it and stops it moving, and light sedation keeps you comfortable while you lie flat. General anaesthesia is used for children, for very long operations or when lying still is difficult. The surgeon places three tiny ports through the white of the eye, removes the vitreous and then carries out the repair, which may include peeling a membrane with fine forceps, flattening the retina, applying laser around tears or removing blood. In some detachments a silicone band is also placed around the outside of the eye. Finally the eye is filled with the chosen tamponade: air that clears within days, a longer-acting gas that lasts about 2 to 8 weeks, or silicone oil that stays until a second operation removes it, usually after a few months. The small openings usually seal without stitches. The operation takes about 30 minutes for a simple membrane peel and up to 2 hours for a complex detachment.

Before surgery, the retina is examined with the pupils dilated and imaged with an optical scan of the macula, and an ultrasound is used when blood blocks the view. Your general health, diabetes control, blood pressure and blood thinners are reviewed, and blood thinners are adjusted only on medical advice. Bring previous scans, reports of any injections or laser treatment and a list of your medicines. If a gas bubble is likely, the team will explain posturing, which means keeping the head in a set position, for example face down, for several days to help a macular hole close or the retina settle. Practise how you will sleep and rest in that position before you travel. Plan to have a companion with you, and book your return only after discussing which tamponade is expected, because the type of bubble decides how long you must stay before you can fly.

After surgery the eye is covered overnight and checked the next day. It may feel gritty and look red, and antibiotic and steroid drops are used for about 4 weeks. With gas in the eye, vision is very blurred at first and you will see the edge of the bubble as a wobbly line that moves down as the gas shrinks. You must not fly while any gas remains, because the bubble expands at altitude and can raise the eye pressure enough to damage sight permanently. The same applies to mountain travel, and you must tell any anaesthetist that you have gas in the eye, since nitrous oxide makes it expand. Air clears in a few days to about a week, the commonly used gases in about 2 to 8 weeks. You will usually wear a wristband as a reminder. Silicone oil does not expand, so flying is possible, but a second visit is needed later to remove it. Avoid heavy lifting and swimming for a few weeks.

Vitrectomy is a common and well-established operation, but it carries real risks. The most frequent effect is cataract: in adults over about 50, the natural lens often clouds within a year or two, and cataract surgery may follow. Eye pressure can rise in the early days, especially with gas or oil, and needs checking and sometimes extra drops. The retina can detach again, so some people need a further operation. Bleeding, infection inside the eye and loss of vision are uncommon but serious. Results depend on the condition and how long it was present: most macular holes close after one operation, distortion from a membrane usually lessens over months, and after a detachment the outcome depends largely on whether the centre of the retina was affected. Report increasing pain, a sudden drop in vision or a new shadow straight away, and keep every follow-up appointment.